Electric switch



April 19, 1932. J. D. HILLIARD ELECTRIC SWITCH Filed July 1, 1929InventoP John D- H L LLLar'd,

HLS Attorneg.

Patented Apr. 19, 1932" UNITED STATES PATENT OFFICE JOHN D w, OI BCHRIEGTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION01!? NEW YORK ELECTRIC SWITCH.

Application filed July 1, 1929. Serial 'No. 875,141.

My invention relates to improvements in electric switches and moreparticularly switches for closing a circuit subject to largecurrentsespecially in case of abnormal cir- 6 cuit conditions. Circuitclosing switches may'be used to avoid contactdestruction as disclosed inUnited States Letters Patent 1,546,172, dated July 14, 1925 and showingtwo switches in series, one to interrupt and N-the other to close acircuit. The closing switch may be subject-tosevere service particularlunder overload and fault cond1- tions. in fact the electromagneticstresses may be so great as to cause distortion of the 1 switch arts andattached conductors and even su cient to prevent closing the switch orto cause-it to open immediately contact occurs. An object of myinvention is to provide an improved high pressure contact switch inwhich the electromagnetic forces involved tend to close the contacts andmaintain them closed whereby the switch closing operation is:facilitated and the necessary contact pressure assured. Another objectof 95 my invention is to provide an improved switch structure whereby toprevent deformation of the parts under the electromagnetic forcesinvolved. F

My invention will be better understood 80 from the'following descriptionwhen considered in connection with the accompanylng drawings and itsscope will be pointed out in the appended claims.

- In the accompanying drawings Fig. 1 is a side elevation of an electricswitch embodying my invention; Fig. 2 is a sectional elevation on theline 2-2 of Fig. 1; and Fig. 3 is a sectional elevation onthe line 3-3of n the electric switch chosen to illustrate m invention, a conductor100 10 is mounte on and insulated from suita le supporting means such asa station partition wall or a switch board' 11 and a bracket 12 securedthereto. The loop "10- is more or less U- shaped and includes tworelatively movable cooperatingcontacts. such as the fixed contact 13 anda movable contact 14 mounted on the free end of a switch blade 15 whichis pivoted at 16 as shown. In order to facililel portions of the loop10. Inasmuch as current flows in opposite directions in these twoportions, the tendency is for them to separate or the loop to straightenso that a pressure dependent on the current is maintained at thecontact-surfaces which as shown are of the high pressure line contacttype. Qbviously, if the switch is used to close a circult in conjunctionwith another for opening the circuit as disclosed in the patentpreviously mentioned, then on moving the blade 15 to engage the contact13, the electromagnetic forces assist the closing operation.

In order to prevent distortion of the loop 10 under the electromagneticstresses due to large currents, I provide a holding means which as shownincludes two insulated tie rods 18 which engage the bracket-12 and ayoke 19 secured to an insulator 20 on the conductor portion 17. In thismanner the insulator 20 is under compression while the rods '18 take thetension so that the materialsare used to withstand the stresses forwhich they are best adapted. The conductor loop leads 21 and 22, one ofwhich such as 21, goes to the circuit opening switch are supported oninsulators 23, 24. The lead 21 which mayform apart of one leg of theloop 10 has mounted thereon the contact- 13 and the insulator 23 is ofcourse under compression for which it is suited. The base ofthe loopincluding the switch hinge is mounted on an insulator 25. The number ofconductor sections or bars is, of course, a matter dependent on'ithecurgrant to be carried. The switch hinge includ ing the pivot may beprovided with resilient means such as a spring 26 for. insuring thenecessary contact pressure between the laminations of the hinge part 27of the loop and the blade 15. In order to prevent cutting at the hinge,suitable means such as grooves 28 for the reception of vided.

In order to open and close the switch any suitable operating mechanismmay be provided. This will in general be so interlocked with the circuitopening switch as to secure the proper sequence of operation asdisclosed in the patent previously mentioned. The operating mechanismshown includes an op: erating member suchas a shaft 29 to which theblades 15 of the different poles of the switch are connected by rods 30.The shaft may be biased for circuit opening movement by a spring 31. Forclosing a solenoid 32 may be provided. The shaft may be locked in thecircuit closing position by a latch *33 under the control of a trip coil34. The circuit of the closing solenoid and trip coil may be controlledby switches 35 and 36 respectively arranged to be operated in anysuitable manner.

Switches of the type embodying my invention may be used in arrangementswhere the phases are isolated by walls or partitions. Thus the switchesmay be double or triple pole with the poles in the different phasesseparated by walls 37 as indicated in Fig. 2. In this case, ashort-circuit for example may mean large currents in opposite directionsin two adjacent switch blades 15. The tendency is then for the blades tobe displaced out of the plane of the loop 10. In order to avoid this, Iprovide a bracing means which, as shown, includes a sliding connectionbetween the walls 37 and the blade 15. This connection may be of auniversal joint type and includes a socket 38 pivotally secured to theblade 15 near the free end and a plunger 39 pivotall secured to andinsulated from the walls 3 When the switch is closed, the

plunger 39 and the socket 38 form a brace, the

length of which can increase upon blade opening movement to allow forthe angular movement of the blade.

Where two or more blades are actuated from the same shaft 29,thecontacts-l3' and 14in the different poles may not readily come to thesame contact pressure due to variations in alinement, etc. In order toeliminate this difiiculty and yet be sure of high contact pressure, Iprovide a high pressure yielding means between the operating rod 30 andthe switch blade. As shown, this means includes a transverse member 40pivotally secured to the rod 30, a transverse member 41 secured to theblade 15 and between these members springs 42,- the compression of whichwill be according to the desired initial contact pressure.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is, 1 An electric switch including a conductor loop having twoapproximately parallel portions, and means for obtaining a switchcontact pressure dependent on the electromaglubricant may be proneticforces induced by a flow of eurrentin the loop when the switch is closedincluding a fixed contact mounted in one of said portions, and a coocrating contact mounted in said one of sai portions for movement betweenthe fixed contact and the other conductor portion.

2. An electric switch including a fixed contact, a U-shaped conductorand means for obtaining a switch contact pressure dependent on theelectromagnetic forces induced by a flow of current in said conductorwhen the switch is closed including in one leg of said conductor aportion thereof. angularly movable between the fixed contact and theother leg of theconductor.

3. An electric switch including a fixed contact, a U-shaped conductorand means for obtaining a switch contact pressure dependent on theelectromagnetic forces induced by a flow of current in said conductorwhen the switch is closed including a switch blade pivotally mounted inone leg of said conductor and movable between said contact and the otherleg of the conductor.

4. An electric switch includin a U-shaped conductor and means forobtaining a switch contact pressure .dependent on the electromagneticforces induced by a flow of current in said conductor when the switch isclosed including two relatively movable cooperating contactsone mountedin a leg of said conductor and the other mounted 1n said 1e for movementbetween said one contact an other leg of the conductor.

5. An electric switch including a U-shaped the conductor and means forobtaining a switch contact pressure dependent on the electromagneticforces induced by a flow of current in said conductor when the switch isclosed including a fixed contact mounted in a leg of said conductor, anda cooperating switch blade mounted in said leg for movement between thefixed contact and the other leg of the conductor.

6. An electric switch including a conductor loop having two portions forcarryin current in opposite directions, and means or obtaining a switchcontact pressure dependent on the electromagnetic forces induced by aflow of current in said loop when the switch is closed including a fixedcontact mounted in one of said portions and a cooperating-contactmounted in said one portion for movement between the fixed contact andthe other portion of the conductor.

7. An electric switch including a fixed contact and a U-shaped conductorincluding in one leg a pivoted switch blade movable between said contactand the other leg of the conductor, an operating member for actuatingsaid blade and. a relatively high pressure resilient connection betweenthe operating member and the blade. I

8. An electric switch including a conductor loop having twoapproximately parallel portions, one ofsaid portions including pivotalswitch blade movable in the plane of said loop, a contact mounted in oneof said loop portions adjacent the free end of said blade and on theside thereof opposite the other portion, means for actuating said bladeand a fyieldin'g connection between said means and the blade. 9. Anelectric switch including a conductor loop having two approximatelyparallel portions, one of said portions including pivoted switch blade,a contact mounted in one of said loop portions adjacent the free end ofthe blade and on the side thereof opposite the other portion and meansfor preventing the displacement of said blade out of the plane of saidloop.

10. An electric switch including a conductor loop having twoapproximately parallel portions, a fixed contact mounted in one of saidportions, a cooperating contact mounted in said one of. said portionsfor movement between the fixed contact and the other conductor portionand means for preventing the distortion of said conductor loop under theelectromagnetic forces due to current flowing in opposite directions inthe conductor portions when said contacts'are engaged. 80 11. Anelectric switch including a conductor loop having two portions forcarrying current in opposite directions, a fixed contact mounted in oneof said portions, a cooperating contact mounted in said one of saidportions for movement between the fixed contact and the other conductorportions, means for preventing the distortion of said conductor loopunder the electromagnetic forces due to current flowing in oppm 40 sitedirections in the conductor portions Y when said contacts areengaged andmeans for reventing a displacement of said coop-= eratlng contact out ofthe plane of said loop. In witness whereof, I have hereunto set 4 my.hand this 26th day of June, 1929.

' JOHN D. HILLIARD.

